Hydraulic transmission for tumbletype fabric-treating machines

ABSTRACT

A FABRIC TREATING MACHINE OF THE TUMBLE-TYPE, INCLUDING A FABRIC CONTAINER DISPOSED AT AN ANGLE TO THE VERTICAL AND A HYDRAULIC TRANSMISSION FOR DRIVING THE FABRIC CONTAINER. THE FABRIC CONTAINER IS CONNECTED TO THE PUMP HOUSING ELEMENT AND DUAL RANGE FLOW RESTRICTING MEANS RESTRICT THE PUMP OUTPUT IN EITHER A LOW SPEED OR HIGH SPEED SETTING TO INUCE ROTATION OF THE PUMP HOUSING ELEMENT AND THE CLOTHES CONTAINER ATTACHED THERETO. SPEED CONTROL MEANS ARE INCORPORATED IN THE TRANSMISSION AND OPERATE TO SELECTIVELY VARY THE CONTAINER SEED WITHIN PREDETERMINED LIMITS FOR BOTH LOW AND HIGH SEED SETTINGS.

March 2, 1971 H. A. MGANINCH ETAL mnmumc TRANSMISSION FOR TUMBLE-TYPE FABRIC-TREATING MACHINES Filed June so, 1969 United States Patent 3,566,626 HYDRAULIC TRANSMISSION FOR TUMBLE- TYPE FABRIC-TREATING MACHINES Herbert A. McAninch, Auburn, Ind., and Herbert N.

Underwood, Chicago, Ill., assignors to Borg-Warner Corporation, Chicago, 111.

Filed June 30, 1969, Ser. No. 837,821 Int. Cl. D06f 29/02; F16d 31/08 US. Cl. 6823.7 7 Claims ABSTRACT OF THE DISCLOSURE A fabric treating machine of the tumble-type, including a fabric container disposed at an angle to the vertical and a hydraulic transmission for driving the fabric container. The fabric container is connected to the pump housing element and dual range fiow restricting means restrict the pump output in either a low speed or high speed setting to induce rotation of the pump housing element and the clothes container attached thereto. Speed control means are incorporated in the transmission and operate to selectively vary the container speed within predetermined limits for both low and high speed settings.

SUMMARY OF THE INVENTION This invention relates to fabric treating machines, and more particularly to fabric treating machines of the tumble-type incorporating a hydraulic transmission to drive a fabric container disposed at an angle to the vertical.

Tumble-type washing machines known in the art have generally been driven by electric motors through mechanical reduction gears. This construction involved belts, gears, shafts and the like, which presented considerable difiiculty in maintaining accurate alignment. Another inherent difficulty in such prior art devices was the problem of noisy operation.

One approach which has been developed for fabric treating machines of the horizontal axis type is to use a hydraulically powered reversing cylinder for wash action and a hydraulic powered wringer for drying the clothmg.

An improvement over this design was the approach taken by Wilcox and shown in US. Pat. No. 2,582,810. The fabric treating machine there illustrated is of the horizontal axis type and uses a hydraulic transmission to rotate the fabric container for washing action in a cyclically reversing manner and to rotate the fabric container at high speed in a single direction for centrifugal extraction.

The present invention is directed to providing a fabric treating machine combining the inherent advantages of a hydraulic transmission with the inherent advantages of a tumble-type machine. The present invention is particularly directed to providing a hydraulic transmission adapted to rotate the fabric container in a single direction for both a low speed wash and a high speed centrifugal extraction. This transmission is further adapted to allow the operator to vary the rotational speed between predetermined limits in both of the operating ranges.

BRIEF DESCRIPTION OF THE DRAWING The figure is a schematic view of a hydraulic transmission for a tumble-type clothes washer embodying the principles of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the figure, a fabric treating machine in the form of a washing machine is illustrated comprising a tub 3,566,626 Patented Mar. 2, 1971 10 adapted to hold a laundering fluid and a clothes container 11, both tilted at an angle to the vertical, here illustrated as roughly A hydraulic transmission 12 is illustrated for driving the clothes container 11 in a single direction of rotation to effect either a low speed washing operation or a high speed centrifugal extraction operation. The transmission 12 includes a transmission inner housing generally designated as 13.

An electric motor 15 is provided having a water pump 16 driven thereby for recirculating the water in the clothes container 11 of the automatic washer during wash operation. During the spin operation, the water is dumped to a drain by means of a diverter valve (not shown). The source of power 18 is illustrated for operating the motor 15. The cycle selector switch 19 is schematically illustrated in simplified form, although in a washer installation, this function would be performed by a timer switch mechanism of known construction. Electric leads 21 and 24 inter-connect the source of power 18 with the motor 15. Lead 22 is provided to connect the motor 15 to ground. Lead 23 connects the source of power 18 to switch mechanism 19.

The electric motor 15 includes a rotatable drive member 27 which connects the motor to a hydraulic pump 28. The hydraulic pump 28 includes a pumping element 29 and a rotatable pump housing element 30 operative within a fixed case 31. The pump housing element 30 is attached to the fabric container 11 by the shaft 32. The tub 10 is attached to the fixed case 31, as indicated at 33 and 34.

Any of a number of well-known types of hydraulic pumps would adequately perform the function of the hydraulic pump 28, as for example, the crescent type or the gerotor type, but for reasons that will be later described, it is found that the vane type pump will perform best in the present transmission. For this reason, the hydraulic pump 28 is illustrated as a vane pump.

The pumping element 29 consists of a rotor 36 connected to the rotatable drive member 27 of the electric motor 15. The rotor 36 contains a series of radial slots 37. A plurality of vanes 38 are provided, each vane adapted to slide within a slot 37.

The pump housing element 30 consists of an annular disc mounted eccentric to the rotor 36. A pair of arcuate ports 39 and 41 are formed in the pump housing element 30. The port 41 is an inlet port and the port 39 is an exhaust port. fluid sump 42 is schematically illustrated for convenience at various places in the illustration of the invention, although in the actual construction one fluid sump 42 is provided into which all of the exhaust connections for various elements of the transmission exhaust fluid.

Through rotation of the pumping element 29 in a j counterclockwise direction as viewed in the figure, a hydraulic circuit is established. A fluid conduit 44 is provided to communicate fluid from the sump 42 to port 41 when the hydraulic circuit is established. A fluid conduit 46 is provided to conduct fluid from the port 39 to a fluid inlet 48 to a dual range flow restricting valve 47.

A conduit 49 is provided to conduct fluid from the conduit 46 to a second fluid inlet 51 of the restricting valve 47. A conduit 52 is provided to conduct fluid from the conduit 46 to a relief valve 53. A conduit 54 is provided to conduct fluid from the restricting valve 47 to sump 42.

The dual range flow restricting valve 47 comprises a housing 57 defining a bore 58. The housing 57 further defines an annular peripheral relief 61. A valve member 63 is adapted to slide axially within the bore 58 and has a tapered section 64 including a small end 66 and a large end 67. A cylindrical rod 68 concentric with the valve member 63 extends from the small end 66 of the tapered section 64 outside of the housing 57.

The tapered section 64 coacts with the peripheral relief 61 to define a variable orifice through which fluid is communicated from the hydraulic pump 28 to sump 42. This orifice will hereafter be referred to as the control orifice. Associated with the dual range flow restricting valve 47 is an electric actuator 77 here shown as an electrical solenoid. The solenoid 77 is operative to shift the restricting valve 47 against the force of a spring 78 positioned within the housing 13. The solenoid 77 is connected to the spin terminal of the cycle selector switch 19 by an electrical lead 80. The solenoid is also connected to lead 21 by means of an electrical lead 81.

A speed control mechanism 87 is provided to vary the position of the valve member '63 with respect to the housing 57. This will vary the area of the control orifice hence the amount of restriction which the restricting valve provides to the output of the pump 28. The speed control mechanism 87 includes a control lever 88 suitably attached to a cam 89 and adapted to rotate the cam according to a setting of the control lever 88. A lever arm 90 is provided pivoted about an axis 91 having an end 92 biased to contact cam 89 by a spring 94. The outer end 95 of lever arm 90 is adapted to contact the cylindrical rod 68 and selectively vary the position of valve 63 with respect to the housing 57 in response to positioning of the control lever 88.

The spin relief valve 53 is essentially a pressure relief valve and consists of an orifice 101 defined by the housing 13. The orifice 101 admits fluid to a chamber 102 also formed in the housing 13. A tapered valve member 103 acts within the chamber 102 and is biased to close the orifice 101 by a resilient member 104 here shown as a spring. A fluid conduit 105 serves to communicate the chamber 102 with sump 42.

The operation of the fabric treating machine as shown in the figure and previously described herein, is as follows. The timer or cycle selector switch of the automatic washer schematically represented by switch 19 will first select the wash cycle of operation. The electric motor 15 will be activated to rotate in a counterclockwise direction as viewed in the figure. The pumping element 29 will also rotate counterclockwise, its speed of rotation corresponding to the speed of rotation of the drive member 27.

After the first revolution of the pumping element 29, the vanes 38 will be disposed within their corresponding slots 37 out of contact with the pump housing element 30, eifecting a zero output of the pump 28 since no pumping action is taking place. At a predetermined rotational speed, the vanes will be urged to move radially outward by centrifugal force to contact the pump housing element 30, thereby initiating a pumping action. The desired rotational speed at which pumping becomes efiective can be achieved by properly designing the geometry of the rotor and vanes. The obvious result of using this particular type of hydraulic pump is that it enables the electric motor to build up sufficient speed before imposing a load on it.

Since the wash cycle has first been selected, the housing 57 of the dual range flow restricting valve 47 will remain in the dotted line position shown in the figure The housing 57 is biased to this position by the spring 78. As should be apparent from the drawings and from the description, the variable control orifice which is established between the valve member 63 and the peripheral relief 61 will be relatively large when the housing 57 is in the dotted line position, illustrated in the figure. When the spin cycle is selected and the solenoid 77 is actuated through its electrical connection with the spin terminal of the cycle selector switch 19, the solenoid 77 will urge the housing 57 of the dual range flow restricting valve 47 to move to the solid line position shown in the figure against the force of the spring 78. In this position, a relatively small control orifice will be estab- 4 lished between the valve member 63 and the peripheral relief 61.

As the pumping element 29 rotates in a counter-clockwise direction, fluid will be drawn from the sump 42 into conduit 44 and communicated to the inlet 41 of the hydraulic pump 28. As the fluid is pressurized, it will be delivered from the outlet port 39. Conduit 46 communicates the fluid from the outlet port 39 to bore 58 to act against the valve 63 urging it into contact with the lever arm 90. Fluid is communicated from conduit 46 to peripheral relief 61 by conduit 49 and flows from the peripheral relief to sump 42 through the variable control orifice. As previously explained, the position of cam 89 will determine the size of the variable orifice in this the low speed range, as well as in the high speed range.

By restricting the flow of fluid through the restricting valve 47, we elfectively restrict the output of the hydraulic pump 28 which creates a reaction torque on the rotatable pump housing element 30. This reaction torque induces a rotation of the pump housing element 30 and, through its previously described connection, the clothes container 11 connected thereto. It can now be seen that by varying the position of valve member 63, we vary the area of the control orifice thereby varying the restriction to the flow of fluid from the pump 28. The smaller the control orifice, the less fluid is allowed to pass to sump and the more nearly the rotational speed of the pump housing element 30 approaches the speed of the pumping element 29. The difference in rotational speed between the pump housing element 30 and the pumping element 29 is accounted for mainly by the fluid allowed to leak to sump. If the valve member 6.3 were to completely close off communication between the outlet of the pump 38 and sump 42, assuming zero leakage in the spin circuit, the rotar tional speed of both elements would be substantially the same, the hydraulic fluid becoming trapped in the circuit. The net flow output of the pump would be zero since there would be no relative rotation between the pumping elements resulting in a hydraulic couple between the pumping element 29 and the pump housing element 30. v

If valve member 63 was now moved to allow a slight fluid flow from pump 28 to sump 42, this would allow a slight relative rotation between the elements. Since the rotational speed of pumping element 29 is substantially constant and determined by the speed of electric motor 15 to which it is attached, the result will be a decrease in the rotational speed of the pump housing element 30 and correspondingly, a decrease in rotational speed of clothes container 11.

As the area of the control orifice increases, the flow from pump 28 to sump increases allowing a greater relative rotation between the pump elements and results in a slower speed for clothes container 11. When the valve member 63 is positioned such that it offers virtually no resistance to the fluid flow between pump and sump, we reach the point of minimum rotational speed of the clothes container 11. The reaction on the pump housing element 30 at this time is solely due to the viscous drag between the pump elements.

Thus it has been shown that the speed of clothes container 11 can be selectively varied between a predeterminer minimum and maximum speed over the low speed range by varying the restriction to the output of the hydraulic pump. The same selective speed variation is accomplished over the high speed range in exactly the same manner. A speed range of from 30 r.p.m. to 54 r.p.m. has been found to be adequate for the low speed or tumble range and from 70 r.p.m. to 400 r.p.m. for the high speed or spin range.

When the timer for the cycle selector switch advances from the wash to the spin position, the solenoid 77 will become energized and urge the housing 57 of the dual range flow restricting valve 47 to the solid line position, as shown in the figure, against the force of the spring 78. The control orifice which is established between the valve member 63 and the peripheral relief 61 is now substantially smaller than the control orifice previously described for the wash operation. As a result of the substantially decreased control orifice, a substantially greater restriction is presented to the flow of fluid from the pump 28 to sump 42. Consequently, the pump housing element 30 is spun at a substantially greater speed as is the clothes container 11.

The operation of the fabric treating machine in the spin cycle of operation is substantially the same as in the wash operation previously described. The speed of the clothes container 11 is determined by the speed control mechanism 87 in conjunction with the setting of the cam 89. Any movement of the cam 89 which would move the valve member 63 to increase the orifice size would result in a corresponding decrease in the rotational speed of the fabric container 11.

When the spin cycle is initiated, the torque required to accelerate the clothes container 11 and the wet clothes contained therein from relatively low speed up to relatively high rotational speed is initially quite high. This high starting torque results in a relatively high pressure in the fluid circuit. The spin relief 53 is set to open at a predetermined pressure bypassing some of the output of hydraulic pump 28 to sump until the clothes container 11 has attained a sufiicient velocity and the inertia of the basket and clothes has been overcome. The torque now required to rotate the clothes container 11 is considerably less and the pressure in the spin circuit correspondingly decreases allowing the spin relief valve 53 to close and further allowing the dual range flow restricting means 47 to maintain control over the rotational speed of the clothes container 11.

Various of the features of the invention have been particularly shown and described, however, it should be obvious to one skilled in the art that various modifications may be made therein without departing from the scope of the invention.

What is claimed is:

1. A fabric treating machine adapted to perform a washing operation and a centrifugal extraction operation including a fabric container having a central axis disposed at an angle to the vertical; a positive displacement hydraulic pump including a pump housing element connected to said fabric container and a pumping element; drive means connected to said pumping element of said hydraulic pump; dual range flow restricting means associated with said hydraulic pump positionable in either a low speed or high speed setting for restricting the flow of fluid from said pump to induce rotation of said container by said pump housing element attached thereto, said low speed position operative to effect a relatively low speed tumbling operation and said high speed position operative to effect a relatively high speed centrifugal extraction operation.

2. A fabric treating machine as in claim 1 including speed control means associated with said dual range flow restricting means operative to vary the restriction to said flow in either low or high speed settings thereby varying the speed of rotation of said container over a predetermined range in both the high and low speed settings.

3. A fabric treating machine as in claim 1 including an electrical actuator operatively associated With said dual range flow restricting means, said actuator operative to change the position of said flow restricting means from one setting to another.

4. A hydraulic transmission for a fabric treating machine having a fabric container tilted at an angle to the vertical and adapted to perform a tumble washing operation and a centrifugal extraction operation including a positive displacement hydraulic pump including a pump housing element and a pumping element, one of said elements being connected to said fabric container; drive means connected to the other of said pump elements; a fluid inlet associated with said pump; a fluid outlet associated with said pump; dual range flow restricting means associated 'with the outlet of said pump positionable in either a low speed or high speed setting for restricting the flow of fluid from said pump to induce rotation of said container by said pump element attached thereto, said low speed position operative to effect a relatively low speed tumbling operation and said high speed setting operative to effect a relatively high speed centrifugal extraction operation.

5. A hydraulic transmission for a fabric treating machine as in claim 4 including speed control means associated with said dual range flow restricting means operative to vary the restriction to said flow in either low or high speed settings thereby varying the speed of rotation of said container over predetermined ranges in both the high and low speed settings.

6. A hydraulic transmission for a fabric treating machine as in claim 4 including an electrical actuator operatively associated with said dual range flow restricting means, said actuator operative to change the position of said flow restricting means from one setting to another.

7. A hydraulic transmission for a fabric treating machine as in claim 4 in which said fabric container is connected to said pump housing element and said drive member is connected to said pumping element.

References Cited UNITED STATES PATENTS 2,807,963 10/ 1957 Osterhus et al. 68-24X 3,443,405 5/ 1969 McAninich et al 68-23.7 3,366,015 1/1968 Haas et al 53 RICHARD E. MOORE, Primary Examiner US. Cl. X.R. 6053 

